/*
 * @(#) $Header$
 *
 * Copyright (C) 2010  Daniel Léonard
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package ca.forklabs.crypto.md;

/**
 * This class embodies the algorithm for the message digest SHA-512 according to
 * <a target="external" href="http://csrc.nist.gov/cryptval/shs.html">The Secure
 * Hash Standard</a> document release by NIST. It is more elegant to get an
 * instance with the factory method in class
 * {@link java.security.MessageDigest} :
 * <blockquote>
 * <code>MessageDigest sha512 = MessageDigest.getInstance(ForkLabs.SHA_512, ForkLabs.NAME);</code>
 * </blockquote>
 *
 * @author   <a href="mailto:forklabs at gmail.com?subject=ca.forklabs.crypto.md.SHA512">Daniel Léonard</a>
 * @version $Revision$
 * @see      ca.forklabs.crypto.Forklabs
 */
public class SHA512 extends BigSHA {

//---------------------------
// Class variables
//---------------------------

   /** The name of this message digest. */
   @SuppressWarnings("nls")
   public static final String NAME = "SHA512";

   private static final long[] K = new long[] {
0x428a2f98d728ae22L, 0x7137449123ef65cdL, 0xb5c0fbcfec4d3b2fL, 0xe9b5dba58189dbbcL,
0x3956c25bf348b538L, 0x59f111f1b605d019L, 0x923f82a4af194f9bL, 0xab1c5ed5da6d8118L,
0xd807aa98a3030242L, 0x12835b0145706fbeL, 0x243185be4ee4b28cL, 0x550c7dc3d5ffb4e2L,
0x72be5d74f27b896fL, 0x80deb1fe3b1696b1L, 0x9bdc06a725c71235L, 0xc19bf174cf692694L,
0xe49b69c19ef14ad2L, 0xefbe4786384f25e3L, 0x0fc19dc68b8cd5b5L, 0x240ca1cc77ac9c65L,
0x2de92c6f592b0275L, 0x4a7484aa6ea6e483L, 0x5cb0a9dcbd41fbd4L, 0x76f988da831153b5L,
0x983e5152ee66dfabL, 0xa831c66d2db43210L, 0xb00327c898fb213fL, 0xbf597fc7beef0ee4L,
0xc6e00bf33da88fc2L, 0xd5a79147930aa725L, 0x06ca6351e003826fL, 0x142929670a0e6e70L,
0x27b70a8546d22ffcL, 0x2e1b21385c26c926L, 0x4d2c6dfc5ac42aedL, 0x53380d139d95b3dfL,
0x650a73548baf63deL, 0x766a0abb3c77b2a8L, 0x81c2c92e47edaee6L, 0x92722c851482353bL,
0xa2bfe8a14cf10364L, 0xa81a664bbc423001L, 0xc24b8b70d0f89791L, 0xc76c51a30654be30L,
0xd192e819d6ef5218L, 0xd69906245565a910L, 0xf40e35855771202aL, 0x106aa07032bbd1b8L,
0x19a4c116b8d2d0c8L, 0x1e376c085141ab53L, 0x2748774cdf8eeb99L, 0x34b0bcb5e19b48a8L,
0x391c0cb3c5c95a63L, 0x4ed8aa4ae3418acbL, 0x5b9cca4f7763e373L, 0x682e6ff3d6b2b8a3L,
0x748f82ee5defb2fcL, 0x78a5636f43172f60L, 0x84c87814a1f0ab72L, 0x8cc702081a6439ecL,
0x90befffa23631e28L, 0xa4506cebde82bde9L, 0xbef9a3f7b2c67915L, 0xc67178f2e372532bL,
0xca273eceea26619cL, 0xd186b8c721c0c207L, 0xeada7dd6cde0eb1eL, 0xf57d4f7fee6ed178L,
0x06f067aa72176fbaL, 0x0a637dc5a2c898a6L, 0x113f9804bef90daeL, 0x1b710b35131c471bL,
0x28db77f523047d84L, 0x32caab7b40c72493L, 0x3c9ebe0a15c9bebcL, 0x431d67c49c100d4cL,
0x4cc5d4becb3e42b6L, 0x597f299cfc657e2aL, 0x5fcb6fab3ad6faecL, 0x6c44198c4a475817L
         };

   /** The length in bytes of the digest. */
   public static final int DIGEST_LEN = 64;

   /** The length in bytes of a block. */
   public static final int BUFFER_LEN = 128;

   /** The size of the H buffer. */
   public static final int H_LEN = 8;

   /** The size of the W buffer. */
   public static final int W_LEN = 80;


//----------------------------
// Constructor
//----------------------------

   /**
    * Constructor.
    */
   public SHA512() {
      super(SHA512.NAME, SHA512.BUFFER_LEN, SHA512.DIGEST_LEN, SHA512.H_LEN, SHA512.W_LEN);
      this.coreInit();
      }


//----------------------------
// Implemented methods from fork.crypto.md.BigSHA
//----------------------------

   @Override
   protected long[] getKArray() {
      return SHA512.K;
      }

   @Override
   protected void resetHBuffer() {
      long[] h = this.getHBuffer();
      h[0] = 0x6a09e667f3bcc908L;
      h[1] = 0xbb67ae8584caa73bL;
      h[2] = 0x3c6ef372fe94f82bL;
      h[3] = 0xa54ff53a5f1d36f1L;
      h[4] = 0x510e527fade682d1L;
      h[5] = 0x9b05688c2b3e6c1fL;
      h[6] = 0x1f83d9abfb41bd6bL;
      h[7] = 0x5be0cd19137e2179L;
      }

   }
